Telegraph receiving or repeating circuit



Oct. 11, 1932. A. E. FROST 1 5 TELEGRAPH RECEIVING 0R REPEATING CIRCUIT I Filed'April 10, 1950 4 Sheets-Sheet 2 STOPPING RING S ef/vauve eaves 4/A/5 N21 @[A/D/A/G fPl/Ves LINE N 2 Imventor Ajberi Z. [500% dtwo/lve LINE/W1 13 r attorney Oct. 11, 1932. A. E. FROST Filed April 10. 1930 TELEGRAPH RECEIVING 0R REPEATING CIRCUIT- 4 Sheets-Sheet 3 Y 1 II I i /15 BK RECEIVING 19 PICK (.0 RINGS 1 LINE L 5' U 1 H P Q 804/0 fi/lvs 'JA Bk 60140 RING "a";

GENO/N6 Ll/VE' 3nnentor 6 W (Ittorneg 0a. 11, 1932. AqE. FROST 1,881,458

' TELEGRAPH RECEIVING 0R REPEATING CIRCUIT Filed April 10; 1930 4 Sheets-Sheet 4 Gttorneg Patented Oct. 11, 1932 UNITED STATES PATENT OFFICE ALBERT E. FROST, OI BROOKLYN, NEW YORK, ASSIGNOB. TO THE WE8TEBN ONION TELEGRAPH COMPANY, OF NEW YORK,

TELEGRAPH RECEIVING Application filed April 10,

This invention relates to telegraph receiving or repeating circuits, and in particular to circuits employing relay devices of the thermionic type hereinafter described, wherein the grid serves only to start the tube into operation.

An object of this invention is to devise circuit arrangements for employing thermionic tubes for repeating telegraph signals into a printer or other recorder or from one line to another.

A further object of the invention is to devise circuit arrangements whereby a thermionic tube device may be utilized for controlling the retransmission of both positive and negative si al impulses.

A further ob ect is to devise a telegraph repeating relay for filling in attenuated'signal impulses.

Still another object is to devise a telegraph repeating system in which the signals from one line are stored up and retransmitted over a plurality of lines.

My invention is illustrated in the accompanying drawings in which:

Figure 1 illustrates a simple repeating arrangement employing two thermionic tubes for repeating telegraph signals from one line to another.

Figure 2 illustrates a repeater employing four thermionictubes for storing up the signals from a receiving line and retransmitting the signals to two sending lines.

Figure 3 illustrates a repeater system for filling in impulses which have been attenuated.

Figure 4 shows a relay system employing two thermionic tubes, one of which operates on positive impulses and the other operates on negative impulses.

Figure 5 shows a repeating arrangement employing two thermionic tubes in pushpull relation for repeating telegraph signals from one line to another, statically, without any moving parts and without employing a magnetic circuit.

The special device, or thermionic tube, employed in my invention comprises gas-filled thermionic tubes of such construction that when the anode is connected to positive bat- .N. Y., A CORPORATION 01' NEW YORK OR REPEATING CIRCUIT 1980. Serial No. 443,812.

. tive ions and has no further effect in controlling the plate current. This sheath, usually only a fraction of a millimeter thick, contains the whole voltage drop between the grid and the space surrounding it. Chan ing the grid voltage merely changes the thicl rness of the sheath and has no effect on the potential of the rest of the space. Hence the grid is powerless to stop the late current, once it is started. It can only e stopped by removing the plate volt e. be unstable with a free gri and hence a small negative potential is normally applied to the grid to keep the tube from starting.

The function of the grid may therefore be likened to a trigger. The amount of power required to start the tube is exceedingly small. A thermionic tube having the characteristics described is disclosed in patent to Irving Langmuir No. 1,289,823. The name thyratron has been applied to tubes of this type in an article entitled Gas-Filled Thermionic Tubes by A. W. Hull published in the Journal of the American Institute of Electrical Engineers, November 1928, page 802, in which other suitable forms are described.

Referring to Figure 1, L represents a receiving line, and L a sending line. Numerals 1 and 2 indicate gaseous thermionic tubes of the type described above. One side of the incoming or receiving line L is connected to the solid ring 4 of the pick-up rings of the distributor equipment, which is provided with rotating brushes BR and BR operated in synchronism with the incoming signals. Alternate segments 5 of the segmented pick-up ring are connected to the grid of tube 1, and the remaining segments 6 are connected to the grid of tube 2. The other side of the receiving line L is connected to the cathodes of tubes 1 and 2'. One side of the sending line L is connected to the cathodes of vacuum tubes 1 and 2 through a battery B The other side oi the sending line is The tube may 'ing line.

connected to the solid ring 7 of the transmitting rings. Alternate segments 8 of the segmented transmitting ring are connected to the plate of tube 1, and the remaining segments 9 of this ring are connected to the plate of tube 2. A battery B and aresistance R are connected in series across the terminals ofsending line L,,b-atte'ries B and B being properly poled to supply plate current to tubes 1 and 2 through the transmitting rings. C indicates a battery connected between the cathode and grid of tube 1 through a limiting resistance r for ma ntaining the grid negative when the input circuit is disconnected from the grid circuit, and a battery C and resistance 1' are provided in connection with tube 2 for the same purpose.

The operation of Figure 1 is as follows:

Brushes BB and BR: of the pick-up transmitting rings respectively, are rotated in synchronism with the incoming signals. Normally battery B transmits negative current to the left hand side of the sending line L that is when both tubes are deenergized. Tubes 1 and 2 are operated only by positive impulses received from the incoming line, and when a positive pulse is received, one or the other tube will be operated, thereby causing a current to flow in the plate c rcuit. The constants of the plate circuits are so adjusted that when either tube is energized,

and current is flowing in the plate circuit, the positive polarity of battery B overcomes the negative polarity of battery B in the l ne L, and sitive current is therefore transmitted to the left side L of the sending line.

Hence as long as positive impulses are received in succession on the receiving line, positive current is transmitted to the send- When a negative impulse is received over the line L, neither tube is started and no current flows in the tube circuits and the circuit of battery B is open. Accordingly battery B transmits negative current to the sending line L,.

In Fig. 2 there is shown a system for receiving and storing signals from one line and retransmitting the signals alternately into each of two other lines. Four thermionic tubes 1 to 4 are employed, the cathodes of which are connected to one side of receiving grid of tube 3 and segments 4, 8, 12 etc. are

connected to the grid of tube 4. The left hand sides of sending lines No. 1 and No. 2 are connected to the cathodes of tubes 1 to 4 through a battery B The plate elements of tubes 1 to 4 are connected to the common cathode terminal conductor 15, through battery B and resistances R to B respectively. The plate element of tube 1 is also connected to segments 4, 8, 12 etc. of the segmented stopping ring; the plate element of tube 2 is also connected to segments 2, 6, 10 etc. of said ring; and the plate of tube 4 is connected to segments 3, 7, 11 etc. of said ring. The solid stopping ring 16 is connected to the common cathode terminal 15 through a battery B, with the negative terminal of the battery connected to the ring. Alternate segments of the sending rings for line No. 1 are connected to the plate of tube No. 1, and the remaining segments for line No. 1 are connected to the plate of tube No. 3. In like manner, alternate segments of line No. 2 sending rings are connected to the plate element of tube 2, and the remaining segments are connected to the plate of tube No. 4. The solid rings 17 and 18 of the two sending rings, are connected respectively to the right hand sides of lines L and L Battery B is connected in series with a resistance R across the terminals of sending line L and Battery 13,, is connected in series with a resistance R, acros the terminals of line L Batteries B and B are properly poled to supply plate current to' tubes 1 and 3'through the sending rings for line No. 1, and batteries B to B are properly poled to supply plate current to tubes 2 and 4 through the sending for line No. 2.

The operation of Figure 2 is as follows:

It is understood that brushes BR to BR, are rotated in synchronism with the incoming signal impulses. Each tube picks up every fourth pulse from the receiving line. Since the plate circuits for the tubes remain closed at all times through resistances R to R respectively, each tube will remain energized after it is once started until it is stopped by operation of the stopping rings.

- Positive impulses picked-up by tubes 1 and 3 are therefore stored up and retransmitted to sending line No. 1 through sending rings for line No. 1. Positive impulses picked up by tubes 2 and 4 are stored up and retransmitted to sending line No. 2 by sending rings for line No. 2. After a tube has been operated and its signal has been transmitted to the corresponding sending line, some means must be provided for removing the operating potential from the plate of the tube. Battery B connected to the stopping rings is provided for this purpose, and is so poled that when the brush BB of the stopping rings connects negative pole of battery B to the plate circuit of the tube which has been operated, the effect of negative polarity of b aitt ia h b l 1 t ere y app yin a ne ative otentilil to plate of the tube, arid thugstoppiiig the late current.

e tubes "operate only on positive pulses and can there ore transmit only signals of positive polarity. In order to transmit signals of negative polarity, batteries B and B are permanently connected to sending lines L and L, respectively. Thesebatteries normally transmit negative current to the left side of each sending line when no positive si al comes in on the receiving line L.

en a tube is operated by an incoming positive impulse, the circuit constants are such that a itive'signal is transmitted to the line. his is brought about by the effect of the stronger positive potential of the battery l3 overcoming the negative potential of the smaller battery B, or 4 as previously explained in describing Fi 1.

In Figure 3, I have shown a repeater system for filling in signal impulses that have been attenuated to such an extent that they cannot be received. Two thermionic gaseous repeaters 1 and 2 are employed, the cathodes of which are connected together and to one side of receiving line L through a resistance R. The other side of receiving line L is connected through a battery C to the solid pickup ring 19. The distributor equipment includes the solid and segmented pick-up rings, solid transmitting rings A and B, and segmented transmitting rings A and B The pick-up brush BR, and the transmitting rushes BR and BR, are rotated "in synchronism with the incoming signals in the well known manner. Alternate segments of the segmented pick-up ring are connected to the grid of tube 1, and the remaining segments are connected to the grid of tube 2. The plate element of tube 1 is connected to solid transmitting ring A, and the plate of tube 2 is connected to the solid transmitting ring B. The left hand side of sending line L is connected to the cathodes of tubes 1 and 2 through resistance R. The right hand side of transmitting line L is connected through a battery B to segmented transmitting ring A through a resistance R and to segmented transmitting ring B through a resistance R A battery B is connected in series with a resistance R across the terminals of sending line L,.

The operation of Figure 3 is as follows:

With neither tube operating, battery B transmits negative current to the left hand side of sending line L. Tubes 1 and 2 operate only on positive pulses and can, therefore, transmit only signals of positive polarity.

When a tube is operated by an incoming pos= itive pulse, the circuit constants are such that the effect of battery B overcomes that of battery B and positive current is transmitted to the left hand side of line L This is overcomes the positive polarity because the dro of potential across the resistance R pro uces a positive potential at the intersection L which overcomes the negatlve potential produced at thispoint by the battery 13,. 4

If the incoming signal is so attenuated that Its effect is zero at the moment that pick-up brush BB passes over a pick-up segment connected to, say tube 1, the potential from battery C will operate this tube. When the pick-up brush BR passes over the next succeeding pick-up segment, which is connected to tube 2, the tendency of battery C is to cause the operation of tube 2, but since at this moment, due to the fact that current is flowing through resistance R, the potential of the grid of tube 2 has been still further lowered, owing to the drop of potential in resistance R, and is sufficiently negative to prevent its operation. No current will, therefore, be passed through the plate circuit of tube 2. Accordingly a negative potential is transmitted to the left hand conductor of the sending line L by the battery B This alternating operation of tubes 1 and 2 continues as long as the output of the amplifier is zero. In this manner single impulses which are not received, are filled-in by the action of the local circuit and battery C.

111 Figure 4, I have shown a system for operating printer magnets on either plus or minus line signals. A potentiometer resistance P is connected across the terminals of receiving line L. The mid-point of this resistance is connected to the solid pick-up ring through conductor 22. The upper side or conductor 1 of receiving line L is connected to the grid of thermionic tube 1, and the lower side 1- is connected to the grid of thermionic tube 2. The segmented pick-up ring is connected to the cathodes of both tubes. The grids are connected to the cathodes through batteries C and C5 and limiting resistances R and R to maintain the grids of the tubes negative with respect to the cathodes when the circuits are open. The solid receiving ring 21 is connected to the cathodes of the tubes through a battery B which supplies space current to the tubes through the receiving rings. One-half of the segments on the receiving rings are connected to the selecting magnets for printer A, and these magnets are connected to the plate of tube 1. The other half of the segments on the segmented receiving ring are connected to the selecting magnet-s of printer B and these magnets are connected to the plate of tube 2.

The operation of Figure 4 is as follows:

Due to the manner of connecting tubes 1 and 2 to the receiving line L, tube 1 operates in response to a plus signal, and tube 2 operates in response to a minus signal received over line wire 1 When a negative signal impulse is received over the line wire 1 the return wire 1 is of course of opposite polarity flows from battery B through portion 110- or positive and this causes tube 2 to operate. Hence the tube 2 is operated by the positive polarity of the return wire 1, when a negative impulse is transmitted from the distant station and received over the main line wire 1 The plate circuit of tube l is connected to receiving devices which are intended to operate on positive line signals, that is, in this case to the selecting magnets of printer A. In a like manner, the plate of tube 2 is connected to receiving devices which are intended to operate on negative signals received over line wire 1 that is, to selecting magnets of printer B.

In Figure 5, I have shown a repeating arrangement em loying two thermionic tubes in ush-pull grap signals from one line to another,

statically, without any moving parts and without employing a magnetic circuit.

When a positive impulse is received from the receiving line conductor 1,, tube 1 is started. Current then flows from battery B through portion ac of the output impedance R and tube 1. Current also flows from battery B through portion be of the output impedance R conductor 1 the distant end impedance (not shown in diagram) of the outgoing line L, conductor 1 and tube 1. A positive impulse is thereby transmitted to conductor 1 of the out going line L It is assumed that the impedance of the outgoing line plus the distant end impedance is greater than the output impedance R The current flowing from c to a is greater than the current flowing from c to b. Asuming the resistance of ac to be equal to the resistance of be the voltage drop across ac is greater than the voltage drop across 60. There is a potential difierence across ab equal to the difierence of the voltage drops across ac and be. Condenser C; becomes charged to the potential difierence across ab. The top plate p ot the condenser becomes negatively charged with respect to the bottom plate 10 The potential charge on condenser C; may also be expresed as the voltage of battery B minus the sum of the voltage drops across tube 1 and the portion In: of resistance R Now, when conductor 1 of the receiving line becomes negative, conductor 1 becomes positive and tube 2 starts. Then tube 2 starts the potential of plate p of condenser C, falls to a value equal to the voltage drop across tube 2. Plate p which is connected to the anode of tube 1 must sufi'er instantaneously an equal fall of potential. This brings out the anode potential of tube 1 less than zero or negative with respect to the cathode and tube-1 stops.- Current then of the output impedance R and tube 2. Current also flows from battery B through portion as of the output impedance R conductor 1 ,-the distant end impedance of the outgoing relation for repeating teleof clearly disclosing my invention and that various changes inthe circuits for carrying out this invention will be obvious to engineers without departing in any manner from the invention.

This application is a continuation in part of my prior application Serial No. 344,438

filed March 5, 1929.

I claim: a

1. In a telegraph system, an incoming line, an outgoing line, means for normally transmitting negative current over said outgoing line, a thermionic relay device responsive to positive impulses from said'incoming line to transmit positive impulses over the outgoing line, said thermionic device being characterized by anode, cathode and starting electrode elements so constructed and arranged that current continues to flow in the anodecathode circuit unaffected by the potential of the starting electrode after being started by a critical starting potential applied to the starting electrode.

- 2. In a telegraph system, an incoming line, an outgoing line, a plurality of thermionic devices responsive only to impulses of positive potential, the current continuing to flow in the anode-cathode circuit unaffected by variations in said potentials on the starting electrode, a rotary distributor for connectingsaid incoming line to the input terminals of said,devices in synchronism with the incoming signals and means for connecting the output terminals of said devices in succession to the outgoing line.

3. In a telegraph system, a thermionic device responsive only to impulses of positive potential, the current continuing to flow in the anode-cathode circuit unaffected by vari ations in said potentials on the starting electrode, an incoming line connected to said input circuit, an outgoing line connected to said output circuit, and means to interrupt said output circuit in synchronism with the si'g- L nals received on said incoming line.

452 -111 a telegraph system, a thermionic device having input and output circuits, said thermionic device being characterized by anode, cathode and starting electrode elements so constructed and arranged that current continues to flow in the anode-cathode circuit unaffected by the potential of the starting electrode after being started by a critical starting potential applied to the starting other tube, whereby said two sets of signal electrode, a resistance and a source of plate elements are operated by signal currents of current included in said output circuit, a telopposite polarity.

egraph line connected to said output circuit to include said resistance and a portion of said source of current whereby current of one polarity is normally transmitted over said line, the constants of said output circuit being such that when space current is established in said device the current transmitted over said line is reversed in polarity.

5. In a telegraph system, an incoming line, an outgoing line, two thermionic repeaters, each having input and output terminals, said thermionic repeaters being characterized by anode, cathode and starting electrode elements so constructed and arranged that current continues to flow in the anode-cathode circuit unaffected by the potential of the starting electrode after being started by a critical starting potential applied to the starting electrode and a rotary distributor for connecting said lines to said repeaters in alternate succession in synchronism with the incoming signals. v n

6. In a telegraph system, an incoming line, a plurality of outgoing lines, a plurality of thermionic devices, said thermionic devices being starting electrode elements so constructed and arranged that current continues to flow in the anode-cathode circuit unaffected by thev po tential of the starting electrode after being started by. a critical starting potential applied to the starting electrode, means operated in synchronism'with the incoming signals for supplying the successive signals to said devices in rotation, means to interrupt the output circuits of said devices in synchronism with the signals received on said incoming line, and means including said devices or transmitting signals received by certain of said devices to a plurality of outgoin lines.

7. In a telegraph system, a receiving line, a terminal impedance connected to said line, a ir of thermionic tubes, said thermionic tu s being characterized by anode, cathode and starting electrode elements so constructed and arranged. that current continues to flow in the anode-cathode circuit unaffected by the potential of the starting electrode after being started by a critical starting potential applied to the starting electrode, the input circuits of said tubes being connected to said terminal impedance in push-pull relation, distributor equipment including pick-up rings connected in the grid circuits of said tubes and receiving rings, signal responsive elements connected to certain of the segments of the receiving rings and to the plate of one of said tubes, and signal responsive elements connected to the remaining segments of the receiving ring and to the plate element of the characterized by anode, cathode and In testimony w 

